Apparatus for operating alarms or other devices



W. K. HODGMAN. APPARATUS FOR OPERATING ALARMS OR OTHER DEVICES.

APPLICATION FILED MAY 3!. I919.

Patented J an. 27, 1920.

I lnren for UNITED STATES PigTENT OFFICE.

WILLIS K. HODGMAN, OF TAUNTGN, MASSACHUSETTS.

APPARATUS FOR O?ERATING ALARMS OR OTHER DEVICES.

Application filed May 31, 1919.

To all whom it may concern:

Be it known that I, l/VILLIS K. HODGMAN, a citizen of the United States, residing at Taunton, in the county ofBristol and State of Massachusetts, have invented a new and useful Apparatus for Operating Alarms or Other Devices, of which the following is a specification.

My invention relates especially to improvements in fire extinguishing apparatus in which automatic fire sprinklers are used and wherein an alarm is caused to operate by a continuous passage of water, from a main supply pipe, through a connecting pipe to an alarm device whenever one or more sprinklers have been released; and the objects of my improvements are, first, to provide for the positive operation of the alarm when one or more sprinklers are released; and, second, to prevent the premature operation of the alarm by water hammers, pressure fluctuations or leakage in the system.

I attain these objects by the mechanism illustrated in the accompanying drawing, in which-' Figure 1 is a side view of the apparatus with some of the parts shown in vertical section; Fig. 2, a top view of the alarm valve chamber showing a horizontal section on line 2-2 Fig. 1; and Fig. 3 is an enlarged end view of the alarm valve.

Similar numerals refer to similar parts throughout the several views.

The main water passage of the apparatus, as illustrated in the drawing, consists of the flanged T 4, flanged chamber 5, flanged pipe 6 and flanged T 7.

The water supply under pressure enters the lower T 4 from the supply pipe 8 and leaves the upper T 7 through the sprinkler pipe 9 which leads to the usual branching pipes (not shown) equipped with automatic sprinklers.

The heavy check valve 10 is seated water tight upon the annular valve seat 11 of the chamber 5.

A second water-passage, or by-pass, connects the Ts 4 and 7 and consists of the nip ple 12, L 13, nipple 14, flange 15, flange 16, pipe 17, flange 18, alarm valve chamber 19, nipple 20, L 21 and nipple 22.

Loosely fitting in the pipe 17 but seated water tight upon the annular valve seat 23 Specification of Letters Patent.

Patented Jan. 27, 1920.

Serial 1%. 301,027.

of the flange 15 is the light bell-shaped pis ton check valve 24.

Horizontally movable relative to the annular valve seat 25, fixed in the chamber 19, is the alarm valve 26 which is equipped with three ribs 27 27 27 (shown best in Fig. 3.) which enter the valve seat 25 and serve to position the valve 26 without materially impeding the flow of the water when the valve is open.

Loosely mounted on the reduced portion of the special bolt 28, which is screwed tightly into the chamber 19, is the bell crank lever 29 which acts to open the valve 26 when the long end. of the lever is raised by contact with the hub 30 of the piston check valve 24 as the latter reaches its upper position.

The pipe 31 serves to conduct the flow of water, when the valve 26 is open,-to a common form of alarm device consisting of a wheel, within the case 32, which is rotated by the flowing water and sounds the alarm bell 33.

The pin 34, fixed in the chamber 19, acts as a stop to limit the upward swing of the long end of the bell-crank lever 29 which in turn limits the upward movement of the piston check valve 24.

The weight of the piston check valve 24 per square inch of surface exposed to any lifting action of the water in the apparatus is less than the similar weight of the check valve 10.

WVhen the water pressure in the system above the said check valves is reduced due to the opening of one or more sprinklers and the water pressure below consequently acts to lift the check valves, the piston check valve 24 will be the first to lift from its seat and the check valve 10 being heavier will remain seated until a sufficient volume of water has flowed out through the sprinkler pipe 9 to cause the piston check valve 24 to rise in the pipe 17 until it is stopped by pushing the lever 29 against the pin 34.

The movement of the lever 29 causes the valve 26 to open and water to flow through the alarm pipe 31 and cause the alarm to be sounded.

As soon as the piston check valve 24 has been stopped in its upward motion the check valve 10 will lift from its seat sufliciently to continue the steady flow of water through the open sprinkler or sprinklers and the alarm pipe 31.

As the piston check valve 24 rises in the pipe 17 there will be some water pass the valve 24 on account of its loose fit in the pipe 17.

The pipe 17 is made long enough so the upward movement of the piston valve 24 will not be sulficient to open the alarm valve 26 when intermittent differential pressures exist in the system due to water hammers.

When a leakage occurs in the system above the check valves it will gradually reduce the water pressure above the said valves until the piston check valve 24 opens and then, unless the leakage is extraordinary, enough water will pass by the valve 24, on account of its loose fit in the pipe 17 to supply the leakage without causing the valve 24 to rise. far enough to open the alarm valve 26.

I have now described how my invention operates to provide for the positive operation of the alarm when one or more sprinklers are released and alSO how it acts to prevent the premature operation of the alarm by water hammers or leakage in the system, and will proceed to explain how it is adjusted to prevent giving a false alarm on account of pressure fluctuations.

It is well known that in many places the pressure in the public water system is maintained by pumping engines located at a central station and in such cases it is usual to provide a higher water pressure for fires than is maintained for domestic purposes.

It is also well known that in an automatic sprinkler system there are many dead ends filled with air and consequently there would be a considerable fiowage of water through the alarm apparatus on account of the compression of the air in the dead ends it the water system furnishing the water provided domestic and fire pressures as just described. In such a case when using my alarm apparatus the check valves 10 and 24 act as maximum pressure retaining valves for the contents or" the pipes of the spinkler system above them. The shut-off valve 35 in the alarm pipe 31 can be closed temporarily, when the fire pressure is on, for a period long enough to allow the fire pressure to equalize throughout the sprinkler system and the check valves 10 and 24: to become seated again.

The only need of the above described use of theshutbfi valve 35 would be when water is let into the system when first installed, or after it has been drained, as after that the fire pressure is frequently restored and the volume of water in the pipe 17 above the valve 24 is sufiicient to compensate for any leakage in the mean time.

I claim:

1. In an alarm apparatus, a water passage from a source of water supply under pressure to water distributing means, a check valve dividing said water passage into two sections and operable by a difierential water pressure between said sections, a second water passage connecting said sections, a second check valve in said second water passage operable by a less difierential water pressure than said first check valve, an alarm mechanism operable by a flow of water from said water passages, a third water passage connecting said second water passage and said alarm mechanism, a valve normally closing said third water passage, and means whereby said valve is opened by the completion of the prolonged movement of said second check valve when a predetermined difierential water pressure exists between said sections.

2. In an alarm apparatus, a vertical water passage from a source of water supply under pressure to water distributing means, a check valve dividing said water passage into upper and lower sections and operable by a differential water pressure between said sections, a second vertical water passage connecting said sections, a piston check valve in said second water passage operable by a less differential water pressure than said check valve, an alarm mechanism operable by a flow of water from said water passages, a third water passage connecting said second water passage and said alarm mechanism, a valve normally closing said third water passage, and means whereby said valve is opened by the completion of the prolonged movement of said piston check valve when a predetermined difierential water pressure exists between said sections.

3. In an automatic fire extinguishing system, a vertical water passage from a source of water supply under pressure to automatic sprinklers, a check valve dividing said water passage into upper and lower sections and operable by a differential water pres sure between said sections, a second vertical water passage connecting said sections, a piston check valve in said second water passage operable by a less differential water pressure than said check valve, an alarm mechanism operable by a flow of water from said water passages, a third water passage connecting said second water passage and said alarm mechanism, a valve normally closing said third water passage, and a bell-crank lever cooperating with said valve and said piston check valve to open said valve when a predetermined differential water pressure exists between said sections and causes said piston check valve to rise and actuate said bell-crank lever.

4. In an alarm apparatus, a water pas sage from a source of water supply under pressure to water distributing means, a

check valve dividing said water passage into two sections and operable by a diflerential water pressure between said sections, a second water passage connecting said sections, a second check valve in said second water passage operable by a less differential water pressure than said first check valve, an alarm device, and means whereby said alarm device is caused to operate by the completion of the prolonged movement 10 of said second check valve when a predetermined difierential water pressure exists between said sections.

WILLIS K. HOD GMAN. 

